双喷嘴挡板伺服阀非线性建模及其线性化

为从理论上研究喷嘴挡板伺服阀控电液伺服系统的动静态性能,需要建立较精确的电液伺服阀数学模型。考虑伺服阀喷嘴挡板处阀口流动等非线性因素影响,分析电液伺服阀的电信号输入到阀芯位移的输出特性,建立双喷嘴挡板两级伺服阀的非线性数学模型以描绘实际系统;根据实际模型特点,采用输入/输出线性化方法中的非线性状态反馈变换获得局部线性化模型,并通过分析系统零动态稳定性,从理论上证明了线性化模型的有效性。以常规泰勒展开线性化为对象,对提出的输入/输出线性化模型的精确性进行相应的仿真和实际试验对比。结果表明,该方法所建模型更接近实际系统,具有较强的鲁棒性,可用于精确分析实现阀控液压伺服系统的动静态性能。

Nonlinear Simulation and Linearization of Twin Flapper-nozzle Servo Valve

To investigate the dynamic and static performance of electro-hydraulic servo control system in theory,the accurate mathematic model of twin flapper-nozzle servo valve needs to be established.Firstly,for the non-linear effect of flow in twin flapper-nozzle servo valve,the nonlinear characters of valve’s electrical signal input to spool displacement output are analyzed,then a nonlinear model is set up to represent the actual system.Secondly,according to the character of actual system model,the localized linear model is achieved by nonlinear state feedback transforming,which is based on the input-output linearization method.then this model’s validity is proved theoretically by stability analysis of the system’s zero dynamic state.Finally,the linearization model of Taylor series expansion is chosen as the comparative object,the simulation and experiment results are provied to analysis the accuracy of the linear model.Results show that the local linear model achieved by nonlinear state feedback transforming more appropriate for the actual systems and has strong robustness.